某型飞机起落架舱上蒙皮振动测量与分析

目的研究起落架舱上蒙皮裂纹原因。方法通过建立起落架舱有限元模型,进行固有频率特性计算,同时空测故障区域蒙皮的振动加速度以及动应力,对起落架舱蒙皮的振动情况进行分析。结果起落架舱三角区故障区域振动量级大于非故障区域,起落架舱三角区振动功率谱密度最大值的频率区间在200~500 Hz的中频频段,起落架舱三角区结构振动的幅值与飞机的法向过载Ny密切相关,静载大概是动载的100倍。结论飞机机动过载产生的静载远大于振动产生的动载,起落架舱三角区故障区域以静载为主,是造成裂纹的主要原因。

Vibration Measurement and Analysis of a Certain Aircraft Wheel Wells Skin

Objective To research the cause of crack in wheel wells skin. Methods Vibration of aircraft wheel wells skin was analyzed by establishing a finite element model for the wheel well and measuring the vibration acceleration and the dynamic stress of skin on the fault zone by air. Results The vibration magnitude in the trigonum fault zone of the wheel wells was larger than that of the non fault zone. The maximum value of the vibration power spectrum density of the structure was between 200-500 Hz. The vibration amplitude of wheel wells skin was closely related to the normal overload Ny of the aircraft. The static load was about 100 times of the dynamic load. Conclusion The static load generated by aircraft overload is much larger than the dynamic load caused by vibration. The load in the trigonum fault zone of the wheel wells is dominated by static load, which is main cause of crack.